中华绒螯蟹成熟卵形态和超微结构的研究

中华绒螯蟹的成熟卵仅有初级卵膜,无次级和三级卵巢,质膜初期厚而多层,且具皱褶,卵核在卵的发育过程中变化很大,未发见中心粒,内质网和高尔基体均始见于蟹卵发育的初期,皮层颗粒先出现于蟹卵深部,随后移到卵的表层,无滋养细胞,蟹卵由卵泡细胞提供物质,形成卵黄,此外,还可直接从血淋巴内摄取卵黄前身物质。     

中华绒螯蟹窦腺神经末梢及X-器官神经分泌细胞的类型

在电子显微镜下观察了性未成熟的中华绒螯蟹黄蟹的窦腺及X－器官的超微结构。X－器官位于眼柄神经节终髓的腹外侧,与窦腺位置斜相对,窦腺主要由神经分泌细胞的末梢和胶质细胞组成。神经末梢含有大量的膜结构包围的颗粒、线粒体、粗面内质网和许多电子透明的小泡,末梢外周有时可见指状突起。依据颗粒的大小、形状、电子致密度以及胞质特征,可区分出6种类型的窦腺神经末梢及7种X－器官神经分泌细胞。观察了末梢中神经分泌颗粒的胞吐作用方式的释放过程,并且尝试对窦腺不同末梢中的颗粒及X－器官神经分泌细胞中的颗粒作了比较,发现二者之间具有较好的对应性,即电子致密度无大的变化,形态特征相似,只是大小稍有增加。     

中华绒螯蟹光感受器超微结构在昼夜光周期中的变化

用透射电镜以中华绒绒螯蟹光感受器的超微结构进行了研究。光感受器的基本组成单位－－小眼,从远侧端到近侧端是由角膜、４个晶锥细胞形成的晶锥、一个在前端的小网膜细胞和７个纺锤形的小网细胞聚合而成的小网膜以及周围的多种色素细胞构成。这些结构与已知的甲壳动物的光感受器相似。在小网膜细胞中多囊体、板膜体、溶酶体等细胞顺主要集中在细胞核与核下的层面中。通过对黎明、正午、黄昏和夜晚４个时间取的材料的研究,发现小网     

锯缘青蟹窦腺显微和超微结构研究

借助光学和电子显微镜观察据缘青蟹（Ｓｃｙｌｌａ ｓｅｒｒａｔａ）窦腺的形态结构。窦腺位于眼柄视神经节内髓背侧近外髓处。窦腺呈羹状;腺体壁山神经分泌细胞的末梢和神经胶质细胞组成。神经末梢内充满了电子致密的神经分泌颗粒。根据颗粒的大小、形态及电子致密度等特征,可以区分出４种类型的神经末梢。一些末梢中的多形性颗粒可能是由Ⅱ型末梢中的颗粒转变而成的。一些现象表明,神经分泌物质可以通过胞吐作用或一种类似“顶浆分泌”的方式释放,从而说明神经激素的释放可能是多途径的．     

中华绒螯蟹卵子皮层反应的初步研究

中华绒螯蟹每个成熟卵的皮层内约有１２３０００枚皮层颗粒。皮层颗粒略呈球形,直径约０．４μｍ,外围一层薄膜,内含酶多种以及粘多糖,蛋白质等。受精时,一个真正起受精作用的精子穿入卵质膜以后,近穿入下的皮层颗粒破裂,随即破裂由近及远,迅速有序地向四周蔓延,播及全卵的所有皮层颗粒。全部皮怪颗粒因破裂而排出的内含物大部分和卵膜内层组合成坚厚的受精巢,用耿防阻多精受精。同时排出的内含物还引起卵子渗透压的骤升,     

中华绒螯蟹胸神经团神经分泌细胞的显微和超显微结构观察

应用光学显微镜和电子显微镜技术,研究了中华绒螯蟹(Eriocheir sinensis)胸神经团的神经分泌细胞,描述了其显微和超显微结构。依据细胞形态、细胞核、内分泌颗粒和细胞质的特征将胸神经团神经分泌细胞分为3种类型:Ⅰ型细胞最大,胞质中存在许多大小不同的空泡,分泌颗粒数量很少;Ⅱ型细胞中等大小,细胞器发达,分泌颗粒数量较多,形态多样;Ⅲ型细胞最小,分泌颗粒数量最多,细胞器很少。     

盐酸环丙沙星在中华绒螯蟹体内药物代谢动力学研究

应用反向高效液相色谱法对盐酸环丙沙星在中华绒螯蟹雄、雌蟹血淋巴与肌肉内的代谢规律进行了研究。肌肉注射给药后血淋巴中盐酸环丙沙星的浓度立即达到峰值 ,药物开始向肌肉等组织中运转 ,血药浓度在 1h内迅速下降 ,而肌肉中的浓度达到峰值 ;此后无论是血淋巴还是肌肉中的盐酸环丙沙星浓度均缓慢下降 ,到第 12 0h雌、雄蟹中盐酸环丙沙星的浓度均在 1μg·mL-1(g-1)以下 ,到 2 16h均不能检出。研究表明 :中华绒螯蟹血淋巴中盐酸环丙沙星的药物浓度可用一级吸收二室开放模型描述 ,雄、雌蟹的消除半衰期 (T1/ 2 β)分别为 40 .34± 1.48h和 2 2 .0 7±0 31h ;中华绒螯蟹的性别对盐酸环丙沙星在其体内的代谢有较大的影响。     

体重温度及温度驯化对中华绒螯蟹呼吸率的影响

本文用流水式呼吸仪研究了体重,温度及温度驯化对中华绒螯蟹（又名河蟹）的呼吸率的影响。作者首次运用Ｌｏｇｉｓｔｉｃ方程描述了呼吸率与体重和温度的关系。对于河蟹,这种关系可归纳为：Ｒ＝１２８０Ｍ－０．５０／［１＋ｅｘｐ（２．３５１－０．１３８Ｔ）］μｇＯ／（ｇ·ｈ）。温度驯化能导致速率补偿,表现为２５℃驯化河蟹的呼吸率明显低于１０℃驯化河蟹的呼吸率。因温度驯化所导致的速率补偿与眼柄内分泌因子有关。在急性升温的条件下,河蟹呼吸率对温度的反应并不完全遵循ｖａｎ＇ｔＨｏｆｆ－Ａｒｒｈｅｎｉｕｓ定律。在低温区（１０－１６℃）,两种驯化河蟹的呼吸率对温度较为敏感,Ｑ１０值大于２;在高温区（１６－３０℃）,两者均不敏感,Ｑ１０值小于２。这说明速率补偿不仅可通过长时间温度驯化达到,而且在温度急剧变化时能够在很短的时间内发生。这种速率补偿可能涉及一种新的机制。     

脂质营养对中华绒螯蟹幼体肝胰腺超微结构的影响

采用透射电镜技术研究了中华绒螯蟹（Eriocheir sinensis)各期幼体肝胰腺的超微结构,结果表明,蟹的肝胰腺腺管上皮由Ｅ,Ｆ,Ｂ和Ｒ４种细胞组成,其中Ｅ细胞为胚胎细胞,能分化成其他３种细胞;Ｂ,Ｒ和Ｆ细胞均呈,高柱状,腔面有发达的微绒毛,基底部有基膜,呈明显的极性分布;Ｂ细胞粗面内质网丰富,胞质中有１－２个大液泡,起分泌作用,属分泌液;Ｆ细胞内含发达的粗面内质网,还可见酶原颗粒;Ｒ细胞胞质中有丰富的滑面内质网、游离的核糖体和脂肪滴,主要起贮存养人的作用。细胞的连接有紧密连接和中间连接２种方式。与脂质营养缺乏时相比,脂质营养充足的幼体其肝胰腺超微结构有如下特点：Ｒ细胞质中有连多的脂肪滴,线粒体呈饱满的圆形或椭圆形,且膜未见有内陷或萎缩,滑面内质网膨胀成小泡状结构。     

Ultrastructural changes associated with K+-evoked peptide secretion from a neurohemal organ of the crab,Cardisoma carnifex

Summary Electron-microscopic comparison of K⁺-stimulated and unstimulated crab sinus glands reveals significant differences in neurosecretory terminal morphology. Sinus glands exposed to elevated K⁺ saline for increasing periods of time show increasing numbers of exocytotic release profiles, vacuoles, and multilamellate bodies, and a decrease in the number of microvesicles within 10 m of release sites. These morphological changes are well correlated with secretion of red-pigment-concentrating hormone, as determined by bioassay of perfusate from the individual preparations.     

The ultrastructure of the sinus gland of Gammarus oceanicus (Crustacea: Amphipoda)

Summary The sinus gland of Gammarus oceanicus, like that of other crustaceans, is composed of three elements: neurosecretory axons, glial cells and stromal sheath. Five neurosecretory axon types are identified on the basis of granule diameter, shape, and electron density, and axon matrix density. Exocytosis appears to be the major release mechanism of neurosecretory material. The preterminal regions of neurosecretory axons contain axoplasmic reticulum and neurotubules. Their arrangement in the axon and relationship with one another suggest a transport function. Multilamellar bodies are found in the terminal regions of neurosecretory axons. They arise from mitochondria and may be involved in granulolysis.The technical assistance of G.A. Bance, statistical assistance of D. MacCharles and D.W. Hagen, and financial support provided by the University of New Brunswick Research Fund to K.H. are gratefully acknowledged     

Fine structure of the neurohemal sinus gland of the shore crab,Carcinus maenas,and immuno-electron-microscopic identification of neurosecretory endings according to their neuropeptide contents

Summary The sinus gland of the shore crab, Carcinus maenas, is a compact assembly of interdigitating neurosecretory axon endings abutting upon the thin basal lamina of a central hemolymph lacuna. Four types of axon endings are distinguishable by the size distribution, shape, electron density and core structure of their neurosecretory granules. One additional type of axon ending is characterized by electron-lucent vacuoles and vesicles. The axon profiles are surrounded by astrocyte-like glial cells. Various fixations followed by epoxy- or Lowicrylembedding were compared in order to optimize the preservation of the fine structure of the granule types and the antigenicity of their peptide hormone contents. By use of specific rabbit antisera, the crustacean hyperglycemic, molt-inhibiting, pigment-dispersing, and red-pigment-concentrating hormones were assigned to the four distinct granule types which showed no overlap of immunostaining. Epi-polarization microscopy and ultrathin section analysis of immunogold-stained Lowicrylembedded specimens revealed that immunoreactivity to Leu-enkephalin and proctolin is co-localized with moltinhibiting hormone immunoreactivity in the same type of granule. The size and core structure of the immunocytochemically identified granule types vary little with the different pretreatments but, in some cases, to a statistically significant extent. The present results are compared with those from earlier studies of sinus glands in different crustaceans. The methods of granule identification used in this study supplement the classical approach in granule typing; they are easier to perform and more reliable for the analysis of release phenomena in identified secretory neurons supplying the neurohemal sinus gland.     

Synaptic junctions in the sinus gland of the freshwater prawn Palaemon paucidens

Summary Two types of neurosecretory fibers, designated as Type 5 and Type 6 axons, in the sinus gland of the freshwater prawn, Palaemon, establish contact with other neurosecretory axons by means of synaptic junctions. This finding strongly supports the view that release of some neurohormones from the eyestalk may be regulated by neurosecretory neurons through synaptic transmission.The author wishes to express his sincere appreciation to Prof. T. Aoto for his invaluable advice during the course of this study, to Mr. S. Kubota for collecting the material, and to Mr. Y. Takakuwa for his excellent assistance in electron microscopy     

河蟹MTXO细胞的离体培养和细胞学研究

对河蟹眼柄神经分泌细胞的细胞学进行了研究,建立了河蟹眼柄视神经节终髓Ｘ器官（ＭＴＸＯ）细胞原代培养的实用方法。ＭＴＸＯ神经分泌细胞在添加了谷氨酰胺和常量抗菌素的Ｌ－１５培养基中表现出快速的再生生长,细胞生长可保持３～５天,维持存少约８天。在ＰＨ６．８～７．８,温度２０℃～２８℃及渗适压９５０～１１００ｍＯｓｍ条件下,均能存活和生长,但在无Ｃａ＾２＋或添加Ｃａ＾２＋通道阻ｄＣｌ２的培养基中不能生长     

Neurosecretory centers from the eyestalk of Siriella armata M. Edw. (Crustacea: Mysidacea): ultrastructural variations during normal and experimentally inhibited molt cycle

Summary The ultrastructure of the medulla interna-medulla externa X-organ (MI-ME Xo)-sinus gland (SG) complex in the eyestalk of Siriella armata is described during the normal and the experimentally inhibited molt cycle. In the normal SG, four types of neurosecretory axon terminals, each containing distinguishable neurosecretory granules, can be described. Thus, type-2 granules are synthesized by G1 neurons forming the MI-ME Xo. The cell bodies and axonal endings of these cells in the sinus gland have been examined at the following molt stages: intermolt (stage C4), premolt (D0 and D2), and postmolt (A1, A2 and B). Changes in ultrastructure of the G1 cells have been monitored and correlated to inhibitions of the molt-and reproductive cycle produced by electrocauterization of the MI-ME Xo. The results obtained suggest that the neurosecretion from the G1 cells exerts a positive influence on molt and brood preparation. The occurrence of a distal group of G1 cells whose axons terminate at a different site from the SG suggests that the neural factors of the MI-ME Xo are diverse and control different physiological activities.     

Neurosecretion in the sinus gland of the fiddler crab,Uca pugnax

The ultrastructure of the sinus gland of the fiddler crab, Uca pugnax, was investigated and found to be similar to that in other crustaceans. Five types of neurosecretory axon terminals were tentatively identified on the basis of the size, shape, and electron density of granules within the axons. Release of neuro-secretory material appears to be by exocytosis.